The MIGDAL Experiment

Direct dark matter search experiments increasingly rely on the Migdal effect, a rare atomic process, to enhance sensitivity to low-mass WIMP-like candidates. The MIGDAL experiment aims to observe and characterise this phenomenon in CF4 and noble gas mixtures.

We employ a low-pressure optical Time Projection Chamber filled with low-pressure gas to observe nuclear recoils induced by an intense DD neutron generator. Our primary choice of gas is CF4, for its avalanche-quenching properties and scintillation in the visible spectrum; the latter of which allows for the tracks to be imaged in high-resolution by a fast, low-noise camera. This is then combined with timing information from an independent ionisation readout to achieve 3D-track reconstruction. Data has been collected using fast neutrons at the Neutron Irradiation Laboratory for Electronics (NILE) at Rutherford Appleton Laboratory in the UK. This talk will discuss the detector’s performance with highly ionising nuclear recoils. Additionally, we will discuss the detector’s capability to operate across a wide dynamic range, crucial for imaging the characteristic Migdal topology.